JPH0649032Y2 - Optical signal receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in the following order.

A. Industrial fields of use B. Overview of the device C. Background art [Figs. 6 and 7] D. Problems to be solved by the device E. Means for solving the problem F. Action G. Embodiments [FIGS. 1 to 5] H. Effect of the Invention (A. Field of Industrial Application) The present invention is an optical signal receiving device, in particular, a television receiver (TV), a video tape recorder (VTR), etc. The present invention relates to an optical signal receiving device for receiving a signal by infrared light in various devices.

(B. Outline of the Invention) In the above optical signal receiving device, the present invention configures a wiring film group and an output circuit that configure the input circuit so that a signal on the output circuit side does not enter the input circuit side. The wiring film groups are each surrounded by the ground wiring film.

(C. Background Art) [Figs. 6 and 7] Many electronic products such as television receivers and video tape recorders can be remotely controlled using infrared light by a remote controller. There is. In such a device capable of remote control, a main body has an optical signal receiving device for receiving a remote control signal by infrared light generated from a remote controller separate from the main body of the device.

In this type of optical signal receiving apparatus, for example, as shown in FIG. 6, a circuit board e having a light receiving element d and the like in a shield case c having a light receiving window b formed in a front plate portion a receives the light. The element d is inserted and arranged so as to face the light receiving window portion b. Several wiring films f having a predetermined pattern are formed on the surface of the circuit board e opposite to the side where the light receiving element d is arranged, and further, an amplification circuit, a limiter, a detection circuit, a decoder, and a pulse generator. A signal processing integrated circuit having circuits and the like, and various electric parts g, such as an aluminum electrolytic capacitor, a ceramic capacitor, and a resistor are mounted.

By the way, the optical signal receiving device is not allowed to occupy a large space because a television receiver and a video tape recorder incorporating the optical signal receiving device are required to be downsized, multifunctional, and high in performance. That is, the optical signal receiving device is also required to be downsized.

On the other hand, since the electric signal obtained by converting the infrared light by the light receiving element is very weak, the gain of the input circuit of the signal processing integrated circuit is made very large, so that the signal of the output circuit is input to the input circuit. It is required not to break into. However, as the device is made smaller, crosstalk from the output circuit to the input circuit is more likely to occur. Therefore, there is a trade-off between downsizing and prevention of crosstalk, and it has been difficult to satisfy both requirements.

Therefore, the inventor of the present application sets the wiring pattern of the circuit board to
As shown in the figure, it was devised to reduce the crosstalk between the output circuit and the input circuit. In the figure, h is an input circuit, i is an output circuit, j is a signal processing integrated circuit, k is a first wiring film formed so as to cross between the input circuit h and the output circuit i, and 1 is a circuit board. The second wiring film formed so as to surround most of the circuit formed in the first wiring film k.
And the second wiring film 1 is kept at the ground level. m is a ground terminal, n and o are other terminals, which are formed by the wiring film of the circuit board. Regarding this technology, Japanese Utility Model Application No. 62-11
Proposed by 8007.

(D. Problems to be Solved by the Invention) By the way, according to the optical signal receiving device as shown in FIG. 7, crosstalk between input and output could be prevented to some extent. However, the second wiring film 1 does not completely surround the output circuit i, which hinders complete prevention of crosstalk between the output circuit i and the input circuit h.

The present invention has been made to solve such problems, and an object thereof is to more effectively prevent crosstalk between an output circuit and an input circuit.

(E. Means for Solving Problems) In order to solve the above problems, the optical signal receiving device of the present invention uses an arm wiring film to form a wiring film group forming an input circuit and a wiring film group forming an output circuit, respectively. It is characterized by being surrounded.

(F. Action) According to the optical signal receiving device of the present invention, the wiring film group forming the input circuit and the wiring film group forming the output circuit are both surrounded by the ground wiring film, so that the input circuit and the output circuit are connected. Is very effectively electrostatically shielded by the ground wiring film. Therefore, crosstalk between the input circuit and the output circuit can be effectively prevented.

(G. Embodiment) [FIGS. 1 to 5] Hereinafter, an optical signal receiving device of the present invention will be described in detail with reference to illustrated embodiments.

1 to 5 show one embodiment of the optical signal receiving device of the present invention. FIG. 1 is a perspective view of the device, FIG. 2 is a circuit diagram, and FIG. 3 is a bottom view of a circuit board. FIG. 4 is a plan view of the circuit board with components attached, and FIG. 5 is a sectional view of the device.

In the drawing, 1 is a case having a rectangular parallelepiped shape whose lower surface is opened, 2 is a light receiving window formed in one corner of the upper surface of the case 1, and 3 is a light receiving described later of a remote control signal receiving circuit incorporated in the case 1. With the light receiving lens of the element (13),
This optical axis and the central axis of the light receiving window 2 are aligned with each other. Reference numeral 4 is a cap for closing the opened lower surface of the case 1, and 5 and 5 are pins protruding from the lower surface of the case 1, which form terminals of the remote control signal receiving circuit.

6 is a circuit board, and wiring films 7i, 7i, ..., 7o, 7 are provided only on the back surface.
o, ..., 7e are formed. 7e, 7i, ... Are wiring film groups forming an input circuit, 7o, 7o, ... Are wiring film groups forming an output circuit, 7e is a ground wiring film, and the ground wiring film 7e is a peripheral portion of the circuit board 1. And has a substantially 8-shaped pattern and occupies one of two regions surrounded by the 8-shaped ground wiring film 7e (the region on the right side in FIG. 3). Wiring film groups 7i, 7i, ... Constituting the input circuit
Are formed. Further, wiring film groups 7o, 7o, ... Which form the output circuit are formed in the other area (the area on the left side in FIG. 3). In FIG. 3, 8i is an area where the components of the input circuit are arranged, and 8o
Is an area in which the components of the output circuit are arranged. Each electric component constituting the input circuit and the output circuit is the circuit board 6
Mounted on the front side of. 9 is a signal processing integrated circuit 10
The signal processing integrated circuit 10 is arranged on the back surface of the circuit board 6 in order to reduce crosstalk with a light receiving element (13) described later. 11, 11,
Reference numerals 11 and 11 are capacitors which are electric parts, 12, 12, 12 and 12 are resistors, and 13 is a light receiving element (PIN photodiode).
The light receiving element 13 is fixed on a shield base 14 attached to the front side of the circuit board 6. The shield base 14 is made of metal and is soldered to the ground wiring film 7e to electrostatically shield between the light receiving element 13 and the signal processing integrated circuit 10 and more completely prevent crosstalk therebetween. Fulfill. By installing this seal base 14, sensitivity and S / N can be increased, and the reach distance of the remote control signal can be lengthened by, for example, about 20 to 30%. Since the ground wiring film 7e occupies the peripheral portion of the back surface of the circuit board 6, one lead of the light receiving element 13 is soldered to the ground wiring film 7e, while the other lead is grounded to the ground wiring film 7e. Wiring film 7i inside
The two leads are separated from each other in the direction perpendicular to the side edge of the circuit board 6 closest to the two leads.

Further, three capacitors except the smallest one among the four capacitors 11, 11, 11, and 11 are aluminum electrolytic capacitors, and noise is generated by charging and discharging. Therefore, the three aluminum electrolytic capacitors
The positions of 11, 11, and 11 should be separated from the position of the signal processing integrated circuit 10 as much as possible.
While the two aluminum electrolytic capacitors 11, 11, 11 are arranged side by side along one side edge of the circuit board 1,
The signal processing integrated circuit 10 is arranged near the side edge opposite to the side edge. Besides, aluminum electrolytic capacitors
The signal processing integrated circuits 10 are arranged on the rear surface of the circuit board 6, while the reference numerals 11, 11, 11 are arranged on the front surface of the circuit board 6. Therefore, it is possible to reliably prevent the noise generated in the aluminum electrolytic capacitor from entering the signal processing integrated circuit 10.

According to such an optical signal receiving device, the input circuit and the output circuit are separately arranged so as not to be mixed, and the wiring film groups 7i, 7i, ... Constituting the input circuit and the wiring film group constituting the output circuit are arranged. .. are surrounded by a ground wiring film 7e, and the ground wiring film 7e separates the input circuit and the output circuit. Therefore, crosstalk between input and output can be prevented.

The proposed circuit board shown in FIG. 7 has terminals m, n,
Since o is formed by a wiring film formed on the back surface of the circuit board and the terminals m, n, and o are projected from one side edge of the circuit board, not only for the wiring film forming the output circuit but also for the input circuit. It was not possible to completely surround the wiring film constituting the device with the ground wiring film. Of course, this is not impossible if a circuit board is used that has wiring films on both sides and can connect the wiring films on the front surface and the back surface through through holes, but such circuit boards are very expensive and the optical signal It causes a significant increase in the cost of the receiving device and cannot be practically used. However, in the circuit board of the present optical signal receiving device, the pins 5 and 5 are provided so as to penetrate the circuit board 6, and the wiring film 7 is formed.
Since the pins 5 and 5 are soldered to the external control signal receiving circuit external terminals, the wiring film 7i,
, and the wiring films 7o, 7o, ... Can be surrounded by the ground wiring film 7e.

Further, since the aluminum electrolytic capacitors 11, 11, 11 which become noise sources are kept away from the signal processing integrated circuit 10 as described above, the noise signal processing integrated circuit 10
It is possible to minimize the invasion into.

Although it is necessary to avoid the occurrence of crosstalk between the anode of the light receiving element 13 and the signal processing integrated circuit 10, the light receiving element 13 is arranged on the front surface of the circuit board 6, and the signal processing integrated circuit 10 is Since it is arranged on the back surface of the circuit board 6 and is supported by the shield base 14, such crosstalk can be prevented more effectively.

(H. Effect of the Invention) As described above, in the optical signal receiving device of the present invention, the wiring film is formed only on one surface of the circuit board, and the signal processing integrated circuit is formed on the wiring film forming surface of the circuit board. An optical signal receiving device having an optical signal receiving circuit which is disposed and has other electric parts including a light receiver mounted on the other surface of the circuit board, wherein the pattern of the wiring film is a wiring film forming an input circuit. It is characterized in that the wiring film groups constituting the group and the output circuit are each surrounded by the ground wiring film.

Therefore, according to the optical signal receiver of the present invention, the ground wiring film effectively electrostatically shields between the input circuit and the output circuit. Therefore, it is possible to more completely prevent crosstalk between the input circuit and the output circuit.

[Brief description of drawings]

1 to 5 are for explaining one embodiment of the optical signal receiving device of the present invention. FIG. 1 is a perspective view, FIG. 2 is a circuit diagram, and FIG. 3 is a rear view of a circuit board. FIG. 4 is a plan view of the circuit board with electric components mounted, FIG. 5 is a sectional view, FIG. 6 is a sectional view of a conventional example of an optical signal receiving device, and FIG. 7 is a circuit of a proposed device. It is a back view of a board | substrate. DESCRIPTION OF SYMBOLS 6 ... Circuit board, 7e ... Ground wiring film, 7i ... Wiring film forming input circuit, 7o ... Wiring film forming output circuit, 10 ... Signal processing integrated circuit, 11, 12 ... Electrical parts, 13 ... Light receiver.

Claims (1)

[Scope of utility model registration request] 1. A wiring film is formed only on one surface of a circuit board, a signal processing integrated circuit is arranged on the wiring film formation surface of the circuit board, and another circuit including a photodetector is provided on the other surface of the circuit board. An optical signal receiving device having an optical signal receiving circuit on which electric parts are mounted, wherein the wiring film pattern has a wiring film group that constitutes an input circuit of the optical signal receiving circuit and a wiring film group that also constitutes an output circuit. The optical signal receiving device is characterized in that each is surrounded by a ground wiring film.